<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">

		body{
			font-size: 0px;
		}

		.box{
			width: 200px;
			height: 200px;
			background-color: pink;
			/*转化为内联块*/
			display: inline-block; 
			font-size: 16px;
			margin: 20px;
		}

		.con{
			width: 200px;
		}

		.con h3{
			font-size: 30px;
		}
		
		.box2{
			width: 200px;
			height: 200px;
			background-color: pink;
			font-size: 16px;
			display: none;
		}

		.con:hover .box2{
			display: block;
		}

	</style>

</head>
<body>
	<div class="box">div</div>
	<div class="box">div</div>
	<br>
	<br>

	<div class="con">
		<h3>文字标题</h3>
		<div class="box2">文字标题说明</div>
	</div>

</body>
</html>